Using QR codes to easy backup and recover GnuPG keys
http://ajdiaz.me/doc/2015/01121-qrcodes-gpgbackup.txt
Version: 2015-12-01
One of the major problems related with some backups, for example GnuPG keys
backup, is that the most secure way to perform this backup is traditional
paper. The old fashion hard copy is most durable backup system ever
invented and, also, is easy to keep safe and recopy.
But, when you move data from the digital world to the real world, these data
can take a lot of bytes or kilobytes. Of course, for megabytes backups or
gigabytes backups, the traditional paper way is not an option, but for
smaller ones is the perfect solution.
The problem that we encounter then is the procedure to recover the data. In
the most usual cases, we need to type all data in a more human
understandable way (base64 for example). There are great tools in that
sense, i.e. paperkey, which outputs a gnupg secret key in a hexadecimal dump
easy to translate. But, in any case, this take a lot of time and is a manual
procedure that is susceptible to human errors.
My solution here is to print QR codes within the data in different blocks
of 20kb (the current specification for QR codes is 29kb bits). Then an
automatic reader can understand the QR code and recompose the lost gpg key
in seconds and without pain.